DPF

[prenshaw2]

Hello all,
I traded in my 2010 Kioti DK45SE Cab for a Kioti Rx7320PC. My old one did not have any type of emissions, DEF, etc. This new one has a Diesel Particulate Filter, is it normal for it to sometimes blow out white smoke/exhaust, especially under higher RPMs? It does not always do it, but when it does, it's very visible and has a distinct odor.

 

[rademamj1]

Yes, white smoke during regen can be normal, and then sometimes it maybe absent during a regen. The sulphur odor during regen is always normal for me. It's the only way I can tell my tractor is doing an automatic regen. Typically it does an automatic regen about every 32 hours, and only when I am running the tractor at a high RPM required to do the job. High RPM jobs for me are rotary cutting, wood chipping and stump grinding. Loader and box blade work are mainly low rpm work and never start an automatic regen. I have done two manual regens during my 330 hours on the tractor, all the rest have been automatic.

Remember during a regen, high rpm is your best friend, because it creates the hot exhaust required to burn the carbon particulates in the DPF.

 

[JimR]

Yes, white smoke during regen can be normal, and then sometimes it maybe absent during a regen. The sulphur odor during regen is always normal for me. It's the only way I can tell my tractor is doing an automatic regen. Typically it does an automatic regen about every 32 hours, and only when I am running the tractor at a high RPM required to do the job. High RPM jobs for me are rotary cutting, wood chipping and stump grinding. Loader and box blade work are mainly low rpm work and never start an automatic regen. I have done two manual regens during my 330 hours on the tractor, all the rest have been automatic.

Remember during a regen, high rpm is your best friend, because it creates the hot exhaust required to burn the carbon particulates in the DPF.

Interesting about the white smoke as I have never seen my NX4510 do that. I smelled a sweet smell but never saw smoke of any kind.

 

[prenshaw2]

Mine looked like I was spraying for mosquitoes one time it did it.

 

[JimR]

Mine looked like I was spraying for mosquitoes one time it did it.

Wow, I absolutely never saw mine do that.

 

[prenshaw2]

Wow, I absolutely never saw mine do that.

When I was grading out my riding ring, RPMs up, it did it for about two minutes and then stopped. Usually takes me about 30 minutes to complete the job, so I guess it used that time to do it. It was at night and the white exhaust was really visible in the lights.

 

[Ortimber]

We have 4 machines with DPF's, and none of them have puffed any smoke at anytime. The smell gives away the fact they are in regen though.

 

[MapleLeafFarmer]

We have 4 machines with DPF's, and none of them have puffed any smoke at anytime. The smell gives away the fact they are in regen though.

X2... same on my end. No smoke ever, sound and smell does change though on our Kubotas

 

[ptsg]

Depending on how plugged the DPF is, it can smoke during regen, usually white smoke. Actually it can even throw small carbon particles still very hot to the point of causing fire ignitions with the right conditions. The manual should have a warning for that, at least on cars it does.

Just don't put your hand in front of the exhaust, even 6" away.... Don't ask me how I know

 

[rademamj1]

Another possible cause of brief white smoke, is the tractor diesel is just warming up and having a very rich fuel mixture, and that would also explain the strong odor. The white smoke should go away after 15mins, due to a hot running engine.

 

[countrybumpkin]

My NX did that a few times during a regen, then started doing it when started when cold. Finally it started throwing a CEL and had to have the injectors replaced, a few years and several hundred hours later not a sign of any smoke.

 

[finn1]

The common rail fuel system goes into a post injection mode during regeneration. The post injection occurs after the normal power stroke and essentially passes fuel through the partially open exhaust valve into the manifold and DPF.

If the DPF is at a relatively low temperature this fuel may result in momentary white smoke until the temperature is high enough for the regeneration reaction to begin.

 

[Threepoint]

Prenshaw2, did you notice whether your regen light was on during the white smoke episodes? From your description, I'm assuming not. Per Countrybumpkin's and Finn1's posts, that might tell us more if it was.

 

[rademamj1]

I assume this fuel rich process is mainly occurring during a regen cycle, and this extra fuel is what burns the particulates out of the DPF. Unburned fuel during a regen comes out as white smoke. It should go away shortly.

I one time shut off the tractor, and just as I was turning the key, saw the regen light is on. Too late. Tractor was already turned off. Waited 1 minute and restarted tractor, and saw for the first time a puff of white smoke. Revving up to 2600 PTO speed, smoke went away and then regen light came back on. Automatic regen continued for 12 mins, and everything was back to normal.

 

[prenshaw2]

Prenshaw2, did you notice whether your regen light was on during the white smoke episodes? From your description, I'm assuming not. Per Countrybumpkin's and Finn1's posts, that might tell us more if it was.

No, the light has not come on yet, only 20 hours on tractor, and 1/2 tank fuel used.

 

[Threepoint]

Wow, if you're getting 20 operating hours on 11 gallons, that RX is just sipping fuel!

No, the light has not come on yet, only 20 hours on tractor, and 1/2 tank fuel used.

 

[prenshaw2]

Wow, if you're getting 20 operating hours on 11 gallons, that RX is just sipping fuel!

I have only used it for moving round bales, splitting firewood, and grading my horse riding ring with a soil pulverizer so far. I just ordered a nova MXZ240 flail mower so it will get some pretty decent usage here in a little while. I am willing to bet my fuel consumption won稚 be so light then LOL.

 

[prenshaw2]

At 29 hours the regen light came on, I set the RPMs up like it said to, and it did it's thing. Ran for 10-15 minutes at higher RPMs and then light went off. All seems well, and this thing is a beast (which is why I got a bigger one) compared to my other one when I cleared out a fence row.

 

[MickeyDBC]

It is tree planting season for us so the tractor gets a lot of idling time (idles for ten minutes and then a couple of minutes of pto speed for the auger - wash, rinse, repeat) and it finally did a non mowing/discing regen. Noticed it was stinking and saw the light on so I set the idle to 1500 and it finished in about ten minutes. It is amazing how good these machines are on fuel. Running all day long like this is less than a gallon an hour.

 

[deserteagle71]

I It is amazing how good these machines are on fuel. Running all day long like this is less than a gallon an hour.

I agree. When I first got my Kubota (20 hp more than my old John Deere) I was sure I'd be burning a lot more fuel per hour doing the same work. I was wrong. Despite having the DPF it is better on fuel than the John Deere.